The research program described in this proposal is based on the hypothesis that women with incontinence have altered pelvic floor muscle function as a result of previous neurologic injury or mechanical disruption of the muscle. We will compare in vitro physiologic response, histology, and histochemistry of the levator muscle in women with incontinence as compared to continent women. The overall objectives of this project are to: i) characterize the in vitro functional status of the levator am in continent, and incontinent women, 2) establish the electrodiagnostic findings which correspond to any abnormalities of muscle function in incontinent women. The immediate specific aims of this pilot project are to: I) determine if the response to physiologic test on muscle biopsies differs in stress incontinent and continent women 2) compare the histochemical, and histological differences in the levator am of these women 3) evaluate the electrodiagnostic evidence of denervation and reinnervation in stress incontinent women as compared to continent women 4) ascertain if women with evidence of neurologic injury on EMG evaluation have diminished muscle strength 5) acquire the preliminary data necessary to validate the experimental design 6) formulate a preliminary notion of the nature and levator anti function and etiology of any dysfunction in women with stress urinary incontinence. This study will allow comparison of the physiologic response measures, histologic findings, muscle strength variables and electromyographic results in stress incontinent and continent women. The study population will include women undergoing surgery for benign gynecologic conditions or stress urinary incontinence. Prior to specimen acquisition subjects will undergo pelvic floor muscle testing, urodynamics and electrodiagnostic testing. The results obtained by the experiments are designed to test the overall objectives and aims and will fill a significant gap in our knowledge regarding levator am muscle malfunction in the pathogenesis of stress incontinence. The complex relationships of muscle function, neurologic insult and muscle strength will only begin to be understood if we break down the different components of incontinence and study them individually.